Parse tree conversion
This module is internal; it is documented because it is where a “no such function or constant” error comes from.
Conversion of a lark parse tree into the backend-neutral AST.
This is where a language’s surface syntax stops mattering: namespaces
(TMath::), the trailing $ on ROOT’s array functions, and the function
and constant aliases are all resolved here, so what comes out is written purely
in the canonical names of formulate.identifiers. A name that resolves to
nothing raises here rather than later.